Xiaomi may bring UHD 4K video recording through a future software update to MIUI camera app, but if you have installed the Oreo based MIUI 8.4.3 Global beta ROM on the device, then you can enable the feature right now. Of course, it requires root access on the device.
Thanks to the XDA contributor Vidhanth, by editing a system file you can bring the 4K recording option to the camera app. We have not tested it, but here is how to edit the system file to get the hidden UHD 4K video recording option on Redmi Note 5 Pro. Note: All below given procedures are very technical and void your device’s warranty. Do it at your own risk. First, you need root access on the phone. To do so unlock the bootloader, install TWRP recovery and flash Magisk or SuperSU through TWRP to get root on the phone. After getting root on the phone, you need to edit a system file. It requires a root- enabled file browser like ES File Explorer installed on Redmi Note 5Pro. – Open ES File Explorer and navigate to /system/etc/device_features/whyred.xml – Find the line that says “support_camera_4k_quality”. – Tap on it and change the value “false” to “true“, then save the file. – Reboot your device.
Open the MIUI camera app, go to Settings, and tap on “Video Quality” and select UHD 4K as your default recording resolution. (Source – XDA)
